Abrasive cylinder for hide treating machines

ABSTRACT

The invention is directed to a machine for operating upon wet hides with a helically ribbed abrasive cylinder. The hide is presented to the cylinder on two supporting rolls which are maintained in spaced relationship with the cylinder so that a band of the hide between the rolls is maintained in engagement with the cylinder by the tension supplied solely by the friction of the hide with the rolls while the hide in being stretched laterally by the action of the helical ribs of the cylinder.

United States Patent Kokoras et al.

Oct. 21, 1975 Leafenmm 51/206 NF 51/206 P X Sohl 51/206 R Koella 1 1 ABRASIVE CYLINDER FOR HIDE TREATING MACHINES [76] Inventors: John N. Kokoras, l0 Martinack Ave; William N. Kokoras, 44

Linden Road, both of Peabody, Mass. 01960 May 10, 1974 FOREIGN PATENTS OR APPLICATIONS [22] Filed:

Appl, No; 468,894 Primary ExaminerDonald G. Kelly Attorney, Agent, or FirmMaurice R. Boitcau Related US. Application Data Division of Ser. No. 149,536, June 3, 1971, Pat. No. 3,813,819

[57] ABSTRACT The invention is directed to a machine for operating upon wet hides with a hclically ribbed abrasive cylin- F4 NM WW5 mm 8 f 0H 2H l m U SL Um NH 55 der. The hide is presented to the cylinder on two supporting rolls which are maintained in spaced relationship with the cylinder so that a band of the hide between the rolls is maintained in engagement with the cylinder by the tension supplied solely by the friction of the hide with the rolls while the hide in being 3 4 N, 2 6 8 R 7 B m 2 N R m 0 t 2 .I H S 5 E N mm W m S h u C D m E & W t N 0 U M .m F 2w m 5 5 51/206 R stretched laterally hy the action of the helical ribs of 51/206 P X the cylinder. 51/206 P X 51/206 NF 3 Claims, 8 Drawing Figures 201,778 3/1878 1,029,406 6/1912 Staynesm.4.......,............. 1,438,098 12/1922 De1zell.,.,,..

2 147 438 2/1939 Hassler U.S. Patent Oct. 21, 1975 Sheet 1 of5 3,913,278

US. Patent 0a. 21, 1975 Sheet 2 of 5 3,913,278

U.S. Patent Oct. 21, 1975 Sheet 3 of5 3,913,278

U.S. Patant 0a. 21, 1975 Sheet 4 of5 3,913,278

US. Patent 0:.21, 1975 Sheet 5 of5 3,913,278

ABRASIVE CYLINDER FOR HIDE TREATING MACHINES This is a division of application Ser. No. 149,536, filed June 3, 1971, and now US. Pat. No. 3,813,819, issued June 4, 1974.

The present invention relates generally to improvements in machines for treating hides and more particularly though not exclusively to machines for automatically performing on the hides an operation called wet wheeling.

Prior to undergoing the tanning process, hides or skins (the terms are used interchangeably) of goats and sheep which are to be made into suede are first fleshed, that is, operated upon by a machine including a rotary knife for removing fatty tissue from the flesh side of the hide. The fleshing process is inadequate for removing all of the fatty tissue from the hide. In order to remove the remainder after the fleshing operation, conventional practice includes the step of wet wheeling which is accomplished by abrading the flesh side of the hide on a large rotating cylinder while manually applying localized pressure to the hide. This wet wheeling process not only removes fatty tissue but is also the first step in the development of the napped surface which is characteristic of suede. The wet wheeling operation however, is tedious and time consuming when performed manually and also produces irregularities in the suede which are frequently not discovered until the processing is completed. The result is that substantial quantities of the product must be downgraded because of the defects stemming from incomplete tissue removal. In summary, the conventional wet wheeling method is a tiresome and time consuming operation which in addition, results in a product lacking in uniformity and frequently having such defects that it must be sold at a lesser price.

It is accordingly a general object of the invention to provide a machine for performing a wet wheeling operation in which the abrading of the hide is completely independent of operator control.

Another general object is to enhance both operator productivity in wet wheeling and to improve the quality and uniformity of the product.

A further object is to abrade uniformly the flesh side of hides to be made into suede leather as a first step in the production of the typical suede nap, and to do so without the danger of burning or otherwise damaging the skin in contact with the abrading implement or tool.

The foregoing objects of the invention are achieved by a machine including an abrasive cylinder and work supporting rolls. According to a feature of the invention, the abrasive cylinder is formed with a herringbone pattern of ribs which spread the hide laterally during the abrading process. Stops are provided to position the work supporting rolls a distance from the cylinder greater than the thickest skin to be processed. Under these conditions, the hide cannot be pinched against the cylinder by the supporting rolls but rather, a band of hide between the lines of centers of the cylinder and each of the support rolls, is held firmly in contact with the cylinder by the frictional engagement of the lower roll with the hide. In order to assist in applying tension to the hide being presented to the cylinder, the two support rolls are coupled to rotate together but the lower roll rotates at a slightly slower speed than the upper roll.

Other features of the invention relate to the construction of the cylinder and to the material of which it is made. The cylinder in operation is subjected to a severe combination of forces since it is both revolved at high speed and axially reciprocated in order to eliminate the possibility of scratching the surface of the hide. In addition, the cylinder is formed with deep grooves which define helical ribs diverging in opposite directions from the center of the cylinder to spread the hide laterally as the outer surface of the ribs performs the abrading operation. The cylinder is cast and balanced as a unitary abrasive body on a shaft having a plurality of equally spaced keys to maintain balance and to prevent loosening of the body on the shaft. In addition, the abrasive body is internally reinforced to resist centrifugal forces. An epoxy resin in which a finely divided natural abrasive is embedded provides the necessary bond to resist the severe forces to which the cylinder is subjected and also to guard against rapid erosion so that the cylinder is assured of a long life by withstanding extended periods of use between dressings.

The foregoing objects and features together with numerous advantages to be derived from the present invention will be more fully understood from a detailed description of an illustrative embodiment taken in connection with the accompanying drawings in which:

FIG. 1 is a view in perspective taken from the right front of a machine according to the invention;

FIG. 2 is a view similar to FIG. I but with parts at the front of the machine removed to show more clearly the interior construction of the machine;

FIG. 3 is a fragmentary detail view showing the mounting of an abrasive cylinder forming a part of the machine together with a device for dressing the work contacting surface of the cylinder to renew it;

FIG. 4 is a view in perspective and on an enlarged scale of the cylinder dressing device also depicted in FIG. 3',

FIG. 5 is a view in right end elevation of the machine of FIGS. 1 and 2;

FIG. 6 is a largely schematic view depicting the presentation of a work piece to the abrasive cylinder;

FIG. 7 is a fragmentary detail view on an enlarged scale and in cross-section showing the interior construction of the abrasive cylinder;

FIG. 8 is a view on a still further enlarged scale showing the outline of a rib forming a part of the abrasive cylinder and in exaggerated proportions the components of the abrasive portion of the cylinder.

Turning now to the drawings particularly FIGS. 1 and 2, it will be seen that the illustrative machine includes a frame comprising base rails 10 upon which are erected vertical side frame members 12 and 14 extending in parallel relationship at the ends of a horizontal front stretcher 16. As also seen in FIGS. 3 and 5, there are provided vertical standards 20 and 22 rising from the upper rear end portions of the side members 12 and 14 respectively. The standards 20 and 22 serve to support bearings for an abrasive cylinder indicated generally at 24 and rotatably supported in pillow blocks 26 and 28 affixed respectively to the standards 20 and 22.

The cylinder 24 is formed with reduced shaft diameters 32 and 34 which fit and extend respectively beyond the pillow blocks 26 and 28. The cylinder 24 is rotated through a multiple groove pulley 36 fitted to the right end of the reduced shaft diameter 34 and engaged by a plurality of Vee-belts 38. In addition to the rotation of the cylinder 24, it is also axially reciprocated a distance of approximately A inch, the rotation being at a speed of approximately 2600 rpm and the reciprocation at the rate of approximately 260 cps by a mechanism which will hereafter be described in detail.

The exterior surface of the cylinder 24 consists of helical ribs 44 defined by grooves 46. The direction of the helix is right hand to the left of an imaginary radial plane bisecting the cylinder 24 and left hand to the right of the plane so that a hide 42, as shown in FIG. 6 is biased from the center toward the ends of the cylinder by the action of the helical ribs. It will also be seen that the ribs 44, which are six in number as shown in FIG. 4, are thicker at their base than at their periphery. This thickening is calculated to provide the same amount of abrading effect upon the hide during each revolution of the cylinder as the cylinder becomes smaller from repeated dressings for renewing the surface as will hereafter be seen. As the surface speed of the cylinder is reduced by the decrease in diameter, a greater amount of abradin g surface contacting the hide during each revolution is required to produce the same abrading effect and hence the ribs 44 are increased in thickness by being tapered approximatley 22% on each side as shown in the drawings. Since the abrading action remains constant regardless of the cylinder diameter there is no necessity to adjust the rotational speed of the cylinder in order to maintain its abrading action as the size of the cylinder decreases.

The cylinder 24 is integrally cast of a mixture including abrasive grains preferably natural Turkish emery of 100 mesh size exaggeratedly shown at 48 in FIG. 8 retained in an epoxy resin matrix 50. The abrasive body consisting of the abrasive grains and epoxy matrix is cast around an enlarged shaft diameter 52 which is provided with four keys 54 to prevent relative rotation of the abrasive body with the shaft. In order to reinforce the cylinder 24 against explosion from centrifugal forces, there is embedded in the body a reinforcing cage 56 comprising longitudinal rods and closed rings which fit over the keys 54 and are thereby centered.

The belts 38 which drive the pulley 36 are in turn driven by a motor 62. The longitudinal reciprocation of the roll 64 is imparted to it by mechanism including a sleeve 64 journalled on the reduced shaft diameter 32. There are depending from the sleeve 64 a pair of spaced-apart straps or ears 66 which embrace and are pivotally connected to an actuating bar 68 disposed in a generally parallel relationship with the axis of the cylinder 24. The bar 68 is longitudinally reciprocated to impart a like motion to the cylinder 24 by means of a shaft 70 which includes an eccentric fitting the interior of the enlarged right end portion of the bar 68. The shaft 70 is rotated at the appropriate speed through its own motor reducer combination 72. The arrangement for imparting the reciprocating motion to the cylinder 24 provides optimum flexibility in that, whenever it is desirable to rotate the cylinder without reciprocation, this is accomplished by merely de-energizing the gear motor 72 while energizing the motor 62 to impart rotation only for purposes of dressing the cylinder, for example.

During extended periods of use, the central portion of the cylinder 24 becomes eroded and the leading edge of the ribs 44 become rounded. When the effectiveness of the cylinder 24 is thus reduced, it is restored by dressing it with a diamond bit 76 which is traversed along the length of the cylinder while the cylinder is being rotated at its normal speed but preferably without being reciprocated. For this purpose, there is provided a dressing mechanism including supporting plates 78 and 80 affixed respectively upon the side frame members 12 and 14. Parallel guide rods 82 extend between the plates 78 and 80 to which they are secured and a traverse screw 84 is disposed between the guide rods. A saddle 86 is guided on the rods 82 and includes a nut which engages a screw 84 for advancing the saddle along the length of the cylinder 24. A slide 88 mounted on the saddle 86 has the diamond bit 76 secured to its forward end and is adjustable toward and away from the axis of the cylinder 24 by means of a screw 90 which is then locked in position by a locknut 92. The screw 84 is turned by means of a removable crank 94 for traversing the diamond bit 76 along the length of the cylinder 24. The diamond bit 76 is preferably in the form ofa metal matrix in which a multiplicity of diamond chips are embedded. Alternatively, dressing may be accomplished using a single diamond but the interrupted nature of the cut would, in all probability, be injurious to such a single diamond. The dressing mechanism permits the surface of the cylinder 24 to be repeatedly dressed, typically decreasing the cylinder diameter from approximately 8 inches when new to approximately 6 inches when it is substantially consumed and must be replaced. Because of the increased thickness of the ribs 44 at their bases, the abrading action remains essentially constant even though the surface speed of the cylinder is reduced as its diameter decreass and the rotational speed remains constant.

As seen generally from FIG. 6, the hide 42 is drawn into contact with the cylinder 24 and forwardly out of the machine by means of a continuously driven feed roll 98 which has a renewable friction producing covering. The feed roll 98 is supported on spring pressed pivoted bars 100 one at each end bearing a pillow block 102 in which the roll 98 is journalled. At its right end, the shaft of the roll 98 carries a sprocket 104 engaged by a roller chain 106 also passing over a drive sprocket 108 and maintained in taut condition by an idler sprocket 110. The sprocket 108 is mounted on the shaft of and driven by an electric motor 112.

The feed roll 98 is urged downwardly by a pair of springs 113, one bearing down on each of the supporting bars 100. Each spring 113 is guided around a threaded rod 114 secured to a post 115 fixedly upstanding from each of the side frame members 12 and 14. The downward motion of the bars 100 is limited by a pair of stop nuts 116 and the spring 113 is compressed by a nut 117 to regulate the amount of force applied to the roll 98.

As seen in FIG. 6, the hide 42 is presented to the cylinder 24 by means of upper and lower support rolls 118 and 120 each journalled at each end in pillow blocks 122 supported at the left end on an arm [24 and at the right end on an arm 126. The rolls 118 and I20 are coupled to rotate together, sprockets 128 and 130 being mounted at each end of each of the rolls 118 and 120 respectively. A roller chain [32 engages each pair of sprockets 128 and 130 and the number of teeth in the sprockets is such that the roll 120 rotates 10% more slowly than the roll 118. In operation the rolls 118 and 120 are advanced to the hide-presenting position depicted in FIG. 6 in which the rolls 118 and 120 are spaced from the cylinder 24 a distance slightly greater than the thickness of the thickest hide 42 to be processed. In advancing the rolls 118 and 120 from the dash line position to the full line position depicted in FIG. 6, the hide 42 is pinched between the upper support roll 118 and the constantly rotating roll 98. As seen from FIG. 6, the support rolls 118 and 120 and the cylinder 24 rotate in a counter-clockwise direction as seen from the right end of the machine, the support rolls being driven by the engagement of the feed roll 98 with the hide 42. Each hide 42 is passed twice through the machine, the hide being turned side for side or 180 after the first pass. A first edge is arranged on the roll 118 so that when the rolls 118 and 120 are advanced to the hide-presenting position, the edge will lie just slightly to the left of the line of centers of the feed roll 98 and the support roll I 18 as seen in FIG. 6. The hide is then drawn upwardly and outwardly away from the cylinder 24 while the abrading action takes place in an abrading zone defined on the cylinder 24 between an imaginary line interconnecting the center of the cylinder 24 with a roll 118 and another interconnecting the center of the cylinder with the center of the roll 120. The hide is placed under tension in the abrading zone by the cylinder 120 which rotates more slowly than the cylinder 118 thereby applying a drag to the hide. After the first pass through the abrading zone, the supporting rolls 118 and 120 are moved to the loading position depicted in dash lines in FIG. 6 and the first edge is reversed being placed below the roll 120 before the hide is again presented to the cylinder 24.

For advancing the rolls 118 and 120 toward the cylinder 24 and for retracting the rolls to the loading posi tion, the arms 124 and 126 are pivoted as shown at 134 in FIG. 1, each on an inverted V support 136 fixedly upstanding from the rails 10.

An arm 138 forms a lever with the arm 124 and similarly an arm 140 forms a lever with the arm 126 for moving the rolls 118 and 120 in and out of the hidepresenting position. The mechanism for this purpose includes an air cylinder 142 having a piston rod 144 upon which is mounted a piston (not shown) which divides the interior of the cylinder into upper and lower chambers as the cylinder is seen in FIG. 1. Mechanism for coupling the piston rod 144 to the arms 138 and 140 includes a shaft 145 journalled in the frame and having an actuating arm 146 keyed to it and pivotally connected to the rod 144, as seen in FIGS. 1 and 5. Also secured to the shaft 145 is another arm 147 which is pivotally connected to a threaded rod 148 forming a part of a lost motion connection with a sleeve 152 pivoted at 156 to the arm 140. There is compressed between a nut on the rod 148 and a shoulder of the sleeve 152 a heavy spring 154. When the piston rod 144 is extended outwardly from the solid line to the dash line position as seen in FIG. 5, the lever 126, 140 is pivoted in a clockwise direction bringing the support rolls 118 and 120 to their hide-presenting position. As this happens, the rod 148 slides in the sleeve 152 and the spring 154 is further compressed as the arm 126 reaches a stop. The lever 124, 138 is similarly coupled to an arm 162 secured to the left end of the shaft 145. The position of the rolls 118 and 120 is determined by stops on the arms I24 and 126 engaging abutments such as that shown at 164 in FIGS. 2 and 5. The stop is in the form ofa screw 166 adjustable in a threaded opening in the arm 124, 126 and locked in position by a check nut 168.

Air is admitted to the upper chamber of the cylinder 142 to cause the rod 144 to extend outwardly by means of a valve operated through connections including a pedal 172. A rock shaft 174 on the end of which the pedal 172 is fixedly supported, is journalled in bearing blocks 176 secured to the machine frame. There is secured to the other end of the rock shaft 174 a short mm 178 pivotally connected to a link rod 180 for operating a valve 182 by being coupled to the valve spool. Connected to the valve 182 are a supply line 184 and lines 186 and 188 connected to the upper and lower chambers of the cylinder 142 respectively. When the pedal 172 is depressed, that is, rotated in a clockwise direction as seen in FIG. 5, the spool of the valve 182 is pulled outwardly thereby connecting the supply line 184 to the upper chamber of the cylinder 142 through the line 186 thereby rocking the arms 124 and 126 to bring the rolls 118 and to their hide-presenting position. When the pedal 172 is returned to the counter clockwise extreme of its travel, the spool of the valve 182 is pushed inwardly, connecting the supply line 184 to the lower chamber of the cylinder 182 through the line 188, thereby returning the arms 124 and 126 and the rolls 118 and 120 to their loading position.

In advance of the air supply line 184 is an air line including a number of control elements. A line 194 is intended to be connected to the shop air supply and is provided with a manual shut-off valve 196. In the line 194 is a solenoid-operated valve 198 coupled to a second solenoid-operated valve 200. The valve 198 is actuated automatically to admit air to the supply line 184 when the motor 62 is energized to drive the cylinder 24. The function of the solenoid valve 200 is to purge the supply line 184 of compressed air to prevent motion of the arms 124 and 126 after the motors 62 and 112 have been de-energized. Between the solenoid valves 198 and 200 and the supply line 184 are a filter 202, a pressure control valve 204 and an oiler 206.

Having thus disclosed our invention what we claim as new and desire to secure by Letters Patent of the United States is:

1. An abrasive cylinder for operating upon a sheet of material comprising an abrasive body formed with a plurality of helical ribs oppositely directed from a radial plane longitudinally bisecting the cylinder, each rib being of sufficient depth and substantially thicker at its base than at its periphery thereby providing a relatively constant abrading effect upon the sheet material when the surface speed of the cylinder is reduced as its diameter is decreased through repeated dressings.

2. A cylinder according to claim 1 further characterized in that the cylinder including the ribs is a unitary body of substantially uniform abrasive content.

3. An abrasive cylinder according to claim 2 further characterized in that it comprises a shaft and a unitary body of epoxy resin bonded to the shaft and finely divided abrasive evenly dispersed throughout the resin body. 

1. An abrasive cylinder for operating upon a sheet of material comprising an abrasive body formed with a plurality of helical ribs oppositely directed from a radial plane longitudinally bisecting the cylinder, each rib being of sufficient depth and substantially thicker at its base than at its periphery thereby providing a relatively constant abrading effect upon the sheet material when the surface speed of the cylinder is reduced as its diameter is decreased through repeated dressings.
 2. A cylinder according to claim 1 further characterized in that the cylinder including the ribs is a unitary body of substantially uniform abrasive content.
 3. An abrasive cylinder according to claim 2 further characterized in that it comprises a shaft and a unitary body of epoxy resin bonded to the shaft and finely divided abrasive evenly dispersed throughout the resin body. 